Disazo dyestuffs



United States Patent DISAZO DYESTUFF S Ernst Keller, Basel, Switzerland, assignor to J. R. Geigy S. A., Basel, Switzerland, a Swiss company No Drawing. Application June 27, 1952, Serial No. 296,079

Claims priority, application Great Britain August 16, 1951 6 Claims. (Cl. 260-187) The present process is concerned with the manufac ture of disazo dyestuffs of good water-solubility which are suitable as cyan components in colour films or papers for making colour records.

It has been found that when diazotised amino-phenylbenzyl ethers or diazotised amino-diphenyl ethers, which may contain in the benzene rings additional substitueuts usually found in azo dyes, particularly additional ether groups, but not water-solubilising acid groups, are coupled with 1-amino-2-alkoxy-(or 2-carboXy-methoxy)- naphthaleue-6- or 7-sulphonic acids and the resultant amino monoazo dyestuffs are further diazotised and coupled in an alkaline medium with a 1.8-dihydroxy or l-amino-(or substituted amino)-8-hydroxy-naphthalene-monoor disulphonic acid, which couples in the ortho position to the hydroxyl group, blue-green disazo dyestuffs of good purity of the general Formula I can be obtained:

o-R H0 x AN=N N=N (803K)" soar wherein A is the residue of a diazotised amino-phenyl-benzyl ether or amino-diphenyl ether as defined above,

R is a lower alkyl or carboxy-methyl grou X is a hydroxyl, amino or alkylamino, arylamino or acylamino group, and

n is an integer having the value 1 or 2.

The compounds used as first components in the invention are obtained by known methods as, for example, by condensation at an elevated temperature of alkali phenolates with nitrobenzene derivatives containing mobile halogens, or of benzyl halides with nitrophenols in the presence of acid binding agents, followed by reduction of the nitro group to the amino group. Of particular suitability as substituents in the benzene rings of the diazo components are alkyl groups, e. g. methyl tertiary butyl, tertiary amyl or iso-octyl groups, and halogens, especially chlorine atoms. Of outstanding value in the process of the invention, however, are amino benzene compounds which contain more than one phenoxy group as, for example, the compounds obtained by the condensation at an elevated temperature of 1.3-dichloro-4-nitrobenzene derivatives with the alkali salts of phenol, its homologues or its halogen derivatives, followed by reduction of the nitro group to the amino group.

The diazotisation of the compounds used as first com- (of which 1-amino-2alkoxy-naphthalene-6- phonic acids with lower alkyl radicles or the carboxymethyl radicle, and in particular l-amino-Z-methoxyor -ethoxy-naphthalene-tS-sulphonic acid are preferred in e process of the invention) is carried out appropriately in weakly acidic aqueous solution or suspension. The diazotisation of the amino monoazo dyestutf is advantageously carried out by the indirect method and the final in the presence of alkalies such as ammonia or sodium carbonate, and of basic accelerators such as pyridine bases. Suitable, in the process of the invention, end components which couple in the ortho position to the hydroxyl group are 1.8-dihydroxy-naphthaleneor l-amino-(or substituted amino)-8-hydroxynaphthalene-monoand disulphonic acids containing a sulphonic acid group in the 4-, 5- or 6-position with respect to the 8-hydroxyl group, the second sulphonic acid group, if present, occupying one of the 2-, 3- and 4-positions depending on the position occupied by the blue-green in colour, the colour being of good In the silver-dye-bleach process of colour photography they only require a short bleaching time, and they can, therefore, used advantageously in the preparation of the cyan layer in colour films or in photographic papers for making colour records. Because of their remarkable afiinity for gelatin the dyestuffs have the great advantage that they have little or no tendency of gelatin layers. The use of the dyestufls in the silverdye-bleach process of colour photography forms the subject matter of our co-pending application Serial No. 296,078 of even date herewith now Patent No. 2,694,636.

The following are examples of dyes of especial value for the said purpose.

Dyesl'ujj A 0 O H; OH NH:

N=N-- N=N (I) S 01H Dyestufi B OCH: OH NnsoOom N=N- N=N 6 50.11

S Oil?! O Q =N8N=NS 1H to litre.

EXAMPLE 1 30.5 parts of l amino 2.4 di (2-methylphenoxy)- benzene are dissolved, most advantageously with alcohol or another suitable solvent and indirectly diazotised at 35. The temperature is reduced to 0 by the addition of ice and a weakly acid to litmus solution of 25.3 parts of 1-amino-2-methoxynaphthalene-6-sulphonic acid is added to the diazo compound. The coupling is completed at a weakly acid to litmus reaction. The aminoazo dyestufi so formed is isolated and then washed until no more 1-amino-2-methoxynaphthalene-6-sulphonic acid can be traced in the filtrate. The damp filter cake is then pasted at room temperature at a weakly alkaline reaction to brilliant yellow, 7.5 parts of NaNOz are added and then at 14 parts of cone. hydrochloric acid are poured in. The product is further diazotised for several hours at 14-16 and any excess nitrite is broken down by the addition of sulphonamic acid, after which the diazo compound is cooled to 0-3. The compound is then, in the presence of pyridine, combined with a soda or an ammonia alkaline solution of 32 parts of 1.8-dihydroxynaphthalene-3.6-disulphonic acid. On completion of the coupling, the dyestuff is salted out and purified by thorough washing or dissolving and recrystallising.

When dry, the dyestufi (which is Dye D above) is a dark powder which very easily dissolves in water with a blue-green colour and it dyes gelatin layers in clear blue-green shades. The gelatin dyeings are characterised by the very good fixation of the dyestuff.

As it is important to produce the dyestuff in the purest form possible, it may be advantageous to isolate the diazo compound of the aminoazo dyestutt' before the coupling. This is of particular advantage when the aminoazo dyestuff is obtained in such a form that it is impossible or very difficult to rinse with 1-amino-Z-methoxynaphthol- 6-sulphonic acid without a residue being left.

EXAMPLE 2 The diazo compound of the monoazo dyestuff described in Example 1' obtained from 1-amino-2.4-di (2-methylphenoxy)-benzene and 1-amino-2-methoxynaphthalene-6- sulphonic acid is coupled at 0-5 in the presence of pyridine to a soda or ammonia alkaline solution of 31.9 parts of 1-amino-8-hydroxynaphthalene-2.4-disulphonic acid. On completion of the coupling, the dyestuff is salted out with common salt and filtered, after which it is purified by thorough washing or dissolving and recrystallising and dried. It forms a dark powder (Dye E above) and dissolves in water with a blue-green colour and dyes gelatin layers a pure blue-green shade.

Other similar dyestuffs which dye gelatin layers a slightly more green shade are obtained if, in the above example, the 1-amino-8-hydroxynaphthalene-2.4-disulphonic acid is replaced by 1-acetylamino-8-hydroxynaphthalene-3.6-disulphonic acid (yielding Dye C above) or l-(p-toluene sulphonyl)-amino-8-hyroxynaphthalene- 3.6-disulphonic acid. A further similar but somewhat less easily soluble dyestufl is obtained if l-methylarnino- S-hydroxynaphtha1ene-4-sulphonic acid is used instead of the end component used in the above example. Another also somewhat more difiicultly soluble dyestuffs is obtained if l-acetylamino-8-hydroxynaphthalene-4-sulphonic acid is used as end component. This dyestufi dyes gelatin in a still more green shade with excellent fixation.

EXAMPLE 3 (is 27.7 parts of l-amino-2.4-diphenoxybenzene are indirectly diazotised as described in Example 1 and coupled at a weakly acid reaction to litmus with 29.7 parts of lamino-2-naphthoxy acetic acid-6-sulphonic acid. On completion of the coupling, the aminoazo dyestufi is isolated and washed until no trace of 1-amino-2-naphthoxy acetic acid-6-sulphonic acid can be found in the filtrate. The dyestuff is than pasted again at 40 at a definite alkaline reaction and the temperature, is afterwards reduced to 10 by the addition of ice, 7.5 parts of NaNOz are added and finally 35 parts of cone. hydrochloric acid are poured in. Further diazotisation is carried out for several hours at 10-12" after which the diazo compound is added, in the presence of pyridine, to a soda or ammonia alkaline solution of 31.9 parts of l-amino- 8-hydroxynaphthalene-3.6-disulphonic acid. The temperature for the coupling is reduced at first by the addition of ice to 2-5 and then allowed to rise slowly to room temperature. On completion of the coupling the disazo dyestutf so obtained is salted out with common salt and filtered. When dry, it is a dark powder.

dissolves very easily in water with a blue-green colour and dyes gelatin layers in pure blue-green shades.

A dyestutf with practically the same obtained if, in the above diphenoxybenzene is replaced by l-amino-2.4-di-(2'- methylphenoxy)-benzene.

EXAMPLE 4 25.6 parts of 2-amino-4'-tert. are diazotised in the usual way at -3 and coupled at a weakly acid reaction to litmus to 25.3 parts of 1- amino-2-methoxynaphthalene-6-sulphonic acid. On completion of the coupling, the dyestutf is isolated and washed until no trace of 1-amino-2-methoxynaphthalene- 6-sulphonic acid can be found in the filtrate. The aminoazo dyestutf is then dissolved at 50 at a weakly alkaline reaction, 7.5 parts of NaNOz are added and the temperature is then reduced to 14' by the addition of ice. Thereupon 25 parts of cone. hydrochloric acid are added and it is diazotised for several hours at 1416. On completion of the diazotisation, the temperature is rdeuced to 5-8" and at this temperature and in the presence of pyridine, the product is coupled with a soda or ammonia alkaline solution of 47.3 parts of 1-(p toluene sulphonyl)-amino-8-hydroxynaphthalene-3.6-disulphonic acid. On completion of the coupling, the dyestufi (Dye B above) is isolated in the usual way and purified by thorough washing or dissolving and recrystallising. It dissolves in water with a blue-green colour and dyes gelatin layers in clear blue-green shades which are characterised by their very good fixation.

A dyestutf (Dye A above) with similar properties but of a somewhat more greenish shade is obtained if, in the above example, the l-(p-toluene sulphonyl)-amino- 8-hydroxynaphthalene-3.6-disulphonic acid is replaced by 1-amino-8-hydroXynaphthalene-3.6-disulphonic acid.

A further similar dyestulf is obtained if 2-amino-4'- octyldiphenyl ether is used as starting product instead of 2-amino-4'-tert. amyl diphenyl ether.

EXAMPLE 5 22 parts of 4-chloro-2-aminodiphenyl ether are diazotised in the usual way and coupled at a weakly acid reaction with 25.3 parts of 1-amino-2-methoxynaphthalene- 6-sulphonic acid. The aminoazo dyestutf when washed is further diazotised as described in Example 4 and, in the presence of pyridine, coupled with a soda or ammonia alkaline solution of 42.3 parts of l-(p-toluene sulphonyl)- amino-8-hydroxynaphthalene 3.6 disulphonic acid. On completion of the coupling, the disazo dyestuff is salted out with common salt, filtered and purified by thorough washing or dissolving and recrystallisation. It dissolves in water with a blue-green colour and dyes gelatin layers in clear blue-green shades which are characterised by their very good fixation.

A similar dyestutf is obtained if, in the above example, the l-(p-toluene sulphonyl)-amino 8 hydroxynaphthalene-3.6-disulphonic acid is replaced by l-benzene sulphonyl-amino-8-hydroxynaphthalene-3.6-disulphonic acid.

A further dyestutf with similar properties but a somewhat more greenish shade is obtained if 1-amino-8-hydroxynaphthalene-2.4-disulphonic acid is used as end product. As has been described in the co-pending application regarding the application of the dyestutfs claimed, this dyestuit requires less time in the bleaching process.

EXAMPLE 6 amyl diphenyl ether 21.3 parts of 2-amino-4-methylphenyl benzyl ether are diazotised in the usual way, coupled with 25.3 parts of 1-amino-2-methoxynaphthalene-6-sulphonic acid, the intermediate dyestulf so formed is purified and as described in the previous example, further diazotised. The diazo compound of the aminoazo dyestulf is coupled, in the presence of pyridine, with a soda or ammonia alkaline solution of 1-amino-8-hydroxynaphthalene-2.4-disulphonic acid. The disazo dyestutf so formed is purified in the usual way. It dissolves in water with a blue-green colour and dyes gelatin layers a pure blue-green shade, but these dyeings have a somewhat less good fixation than those described in Examples 4 and 5.

A dyestuff which dyes gelatin in somewhat more greenish shades is obtained if the l-amino-8-hydroxynaphthalene-2.4-disulphonic acid is' replaced by 1-amino-8-hydroxynaphthalene-3.6-disulphonic acid.

Another dyestufi with similar properties is obtained if,

instead of 2-amino-4-methylphenyl-benzyl ether, 2-amino- 4-amylbenzyl ether is used as starting material.

EXAMPLE 7 30.5 parts of l-aminophenyl-2.4-dibenzyl ether are indirectly diazotised in the usual way at 3-5. The temperature is brought to 0-2 by the addition of ice and a weakly acid (to litmus) solution of 25.3 parts of l-amino- 2 -methoxynaphthalene-6-sulphonic acid is added to the be no trace of 1-amino-2-methoxynaphthalene-6-sulphonic acid in the washing liquor. The dyestuff so purified is then suspended in water at room temperature with a Weakly alkaline reaction and is then diazotised at 14-15".

What we claim is: 1. A disazo dyestuff having the general formula:

selected from 1 and 2.

2. The dyestufi of the formula:

SOsH

OCH:

.a. The dyestufi of the formula:

7 8 4. The dyestufi of the formula: OH: OCH: CH NHCOCH;

. cm 0'11 so?! 5. The dyestufi of the formula: OH; OCH; OH OH on. so-H soda 6. The dyestufl of the formula: OH; OCH: 0H NH C =N8-N=N--som CH| S0311 03H References Cited in the file of this patent UNITED STATES PATENTS 1,504,134 Neelmeier et a1. Aug. 5, 1924 1,855,963 Hentrich et a1 Apr. 26, 1932 2,385,698 Fleischaver et a1 Sept. 25, 1945 

4. THE DYESTUFF OF THE FORMULA: 